Artificial limb



Feb. 10, 1925.

H. M. WITMYER ARTIFICIAL LIME Original Filed Sept. 2, 1922 INVENTOR:

WITNESSES:

ma /5w and Patented Feb. 10, 1925.

PATENT OFFICE.

HARRY M. WiTMYER, or Manama, PENNSYLVANIA.

ARTIFICIAL LIMBI Application filed September 2, 1922, Serial No.585,912. Renewed June 26, 1924.

To all whom "it may concern: I

Be it known that I, HARRY M. VVrrMYnR, citizen of the United States,residing at Manheim, county of Lancaster, and State of Pennsylvania,have invented certain new useful Improvements in Artificial Li mbs,whereof the following is a specification, reference being had to theaccompany ing drawings.

My invention relates generally to artificial limbs and more especiallyto artificial legs.

The primary object of my invention is to secure in an artificial leg,absolute freedom 1 of movement in simulation of the real and toconstruct the same without any, rigid part-s whatever so that by virtueof inherent resiliency, utmost comfort is assured the wearer in the actof walking with avoidance of shocks which might tend to injure or tirethe maimed limb.

Other objects of my invention are to provide an artificial leg havingthe. above; attributes combined with extreme lightness; and withcapacity for permitting adjustmentas to the degree of flexibility tosuit individual conditions of application and use.

This desiderata I attain in a hollow structure of elastic or resilientmaterial having the configuration of the limb which it is to replace andwhich is adapted to be inflated with air or other gas until the desireddegree of flexibility is secured.

Further objects and attendant advantages of my invention will becomereadily apparent from the detailed description of various modified formsof the same which follows, while" its scope is clearly manifested in theappended claims.

Referring to the drawings, Fig. I is an illustration of an artificialleg showing my invention embodied in the simplest form at present knownto me.

Fig. II is a modified embodiment of my iiwention in vertical section;and

Fig. III is an illustration of a portion of an artificial legconstructed in accordance with my invention showing certainmodifications which cooperate to ease movement at the region of theankle and toes, and to absorb shocks induced incidentally to walking.

The structure illustrated in Fig. I and designated comprehensively bythe numeral 1, it will be observed, corresponds exactly in configurationto ahuman limb and comprises a leg portion :2 and a foot portion 3 inintegral formation. The whole is made hollow, with a comparatively thinwall 4, of any suitable elastic or flexible material, preferably rubberwhich possesses both these properties and with provision of an internalcavity or chamber 5. In order that this cavity or chamber may beinflated, the structure is providedat some convenient point, say at thetop, with a valve 6 such as employed in. connection with pneumaticbicycle 0 automobile tires. In cases where extreme lightnesscombinedwith maximum strength is desired, I may incorporate in therubber walls, one or more layers of thin but strong fabric material;

The modification of Fig. II. differs from the first described embodimentin that itis supplemented throughout, with exception, of at the top,with an inner wall 7 which extends substantially in parallelism with themain or outer wall with provision of an interspacial cavity or chamber 8about the structure. As in the first instance a valve 9 is provided forapplication of a suitable pump, but inflation is here restricted to theinterspace 8-.

The type of artificial limb shown in Fig. III may in general beconstructed in accordance with either of the forms hereinbeforeexplained since the modifications about to be described, as will bereadily apparent, are applicable to both of the former. In theembodiment under present consideration, I have interposed at the regionof the ankle a band or zone 10 of rubber which is of a softer qualitythan that of the main portion of the structure so that the utmostfreedom of motion of the foot portion relative to the leg portion of thestructure may be obtained. This softer quality rubber may also beemployed at the heel and toe portions ot the foot as indicatedrespectively at 11 and 12 thereby providing for more ready absorp tionof the shocks incidental to walking.

Any suitable means may be employed in attaching my improved artificialleg to the maimed limb of the wearer, such means forming no part of thepresent invention and being therefore omitted from the drawings.

From the foregoing it will be perceived that an artificial 'legconstructed in accordance with the various modifications disclose-d,taken either singly or collectively l ll 1. An artifical limb comprisingan outer wall of flexible material, and an inner wall coextensivetherewith at every point and in spaced relation to provide aninterspacial chamber or cavity between the walls capable of beinginflated.

2. An artificial limb comprising an integral structure of flexiblematerial with integral segments of the same material but of a softerconsistency interposed at the limb joints for ease of movement at theseregions. i

3. An artificial limb comprising an integral structure composed whollyof rubber, the rubber at the limb joints being of softer or moreresilient quality than otherportions for facilitation of free movementat these regions.

4. An artificial limb corresponding in configuration to a humanextremity comprising a leg portion and a foot portion of flexiblematerial and integralstructure and an inte posed integral ankle portionof the same material but of softer consistency for facilitation of freemovement at this region.

5. An artificial limb coresponding in configuration to a human extremityconstructed wholly of rubber with a leg portion and a foot portioninintegral formation, the rubber of the ankle, toes and heel being of acomparatively softer and more resilient quality than that of otherportions for facilitation of free movement at these regions and forabsorption of shocks incidental to walking.

6. As" an article of manufacture, an artificial limb comprising innerand outer coextensive walls of material possessing elasticity,flexibility and resiliency, said walls being integrally connected at thestump receiving end to'define a conformatory interspace capable ofinflation With a similarly configured inner cavity open to theatmosphere.

7.- Asa-n article of manufacture, an arti ficial limb, of elastic,flexible and resilient material, simulating a human member with acon-formatory interspace capable of inflation and a similarly configuredinner cavity open to the atmosphere.

In testimony whereofll have hereunto signed my name at Manheim, Pa, this30th day of August, 1922.

' HARRY M. lVITMYER.

Witnesses:

JACOB H. NIssLnY, HENRY B, BRANDT.

